1. Field of the Inveniton
The present invention relates generally to dive masks having two distinct lenses. The invention relates more specifically to a two window dive mask having an inner frame bonded directly into a rubber skirt and an outer frame to retain the lenses in place.
2. Background Art
The current state-of-the-art in dive masks employs either one of two construction methods. In the first, a rubber skirt is bonded directly to a single viewing lens (called frameless design). This single lens is the only rigid structural support for the mask. Only a single lens that covers both eyes can be used in this design because if two lenses were used, there would be nothing to keep the lenses aligned in the same plane. If the lenses are not on the same plane, distortion would occur when used underwater. The frameless design has the advantage of fewer parts, more streamlined appearance, lower cost construction, and no potential leak paths. It does not however allow removing or replacing lenses as they are permanently bonded in place. Replacing lenses is desirable to accommodate corrective lenses for those with less than perfect vision.
In the second method, a rigid plastic frame is mechanically attached to the rubber skirt and the rigid frame accepts one or two lenses with a sealing gasket and mechanical retainer to keep them in place (framed design). The frames are typically attached to the skirt with snap-fit plastic pieces or mechanical fasteners (screws). There exist two possible leak paths between the lenses and frame and between the frame and skirt. Framed masks typically provide poorer vision because of the bulk of the frame impinging upon the lens area.
An example of prior art dive masks designed to receive two corrective lenses which can be replaced to accommodate changes in correction, is disclosed in U.S. Pat. No. 6,484,324 to Garofolo. This patent teaches the use of a rubber skirt or face and two distinct frames referred to as a stiff body having a grooved relief extending beyond a pair of lenses and a frame which keeps the lenses in place. Having two distinct visible frames tends to result in a heavy and cumbersome-looking mask which is not hydrodynamic in appearance.